Blue disazo dye.



. [new and useful lmprov ements in Blue Disazo 'HAAGER, a citizen ofGermany, both resinewblue di'sazo dyestuffs of the benzidinseries whichpossess an extraordmarystrong ,aihnity for the woolenfiber; besides theyoring-matters derived from dianisidin; in

UNrrn-n STATES rnrnu'r orrijon.

crrms'rornnn RIS AND ER-NST HAAcEaoFnussntoosr, GERMANY. JliGER, orDUSSELDORF-DLERENDORF,GERMANY.

ASSIGNORS TO CARL BLUE DIsAzo DYE,

Specification of Letters latent.

Patented May 19, 1908.

T o all whom "it may concern: Be it known that we, CHRISTOPHER Rrs, acit zen of the Swiss Republic, and ERNST dents of Dusseldorf, Germany,have invented Dye, pf which the following is a specification. T1118invention relates to the production of may serve for dyeing unmordantedcotton in the usual manner. In order to obtain these dyestuffs, theintermediate products obtainable by combination of the tetrazo compoundsof the benzidin series with one molecule of 2.8 naphtholsulfo-acid(croceinicacid) are further combined with one mole cule of 1.8aminonaphthol 4 -.sulfo acid. They dye unrnordanted cotton aswell aswool in a boiling bath containing Glaubers' salt bluish-violet to pureblue shades especially on wool the shades show a great intensity and aremarkable fastness to fulling; by a further treatment with sulfate ofcopper they also'become very fast to the action of light. The sameaffinity for the woolen fiber is not to be observed by other bluesubstantive disazodyes, for instance the known blue colthe newcombination neither the croceinicacid may be supplied, with the sameeffect, by another naphtholsulfo-acid nor instead of the 1.8 aminonaphthol 4 sulfo acid the known 1.8 aminonaphtholdisulfo-acids may beused. Furthermore there is to be noted that, by effecting thecombination in an in verted manner, that is to say by combining forinstance the intermediate compound from tetraz odianisol and 1.8amin0naphthol-4-sulfo acid (see English Patent No. 16569/ 1892) atsecond place with one molecule of croceimc-acid, a dyestuff is obtainedwhich is practically not identical with the new color, the latterproducing much finer and stronger shades, especially on wool.

The following example shows the manner of carrying out this invention:12.2 kilos dianisidin are converted into the tetrazocompound; then at atemperature of about 0 to 0. sodium carbonate is added till alkalinereaction isattained; then'a solution of 12.3 kilos sodium salt of 2.8naphtholsulfo-acid is left to run into the tetrazocompound; afterstirring for some time, the formation of the intermediate roduct beingaccomplished, an alkaline solut on of 11.9 kilos 1:8aininonaphtholl-sulfo-acid is added; after standing for several hoursthe mass is heated to boiling, the color precipitated with common salt,filtered off and dried. It forms a dark-blue powder with metallicluster, easily soluble in Water, which solution is not changed byaddition of caustic soda-lye; with concentrated sulfuric-acid agreenish-blue solution is ob tained. The coloring-matter dyes'unmordanted cotton as well as wool and mixed goods bright greenish-blueshades; when treated at boiling with sulfate of copper and a littleacetic-acid the shades on wool are dyestuffs form dark powders withmetallic luster, easily soluble in water, soluble in concentratedsulfuric acid with blue color; and dyeing cotton and wool from reddishto greenish blue shades, substantially as hereinbefore described.

2. The herein described new blue disazodycstul'f, obtainable bycombination of the intermediate product derived from one mole cule ofthe tetrazocompo'und of dianisidin and one molecule of 2.8naphtholsulfoacid (croceinic-acid) with one molecule of 1.8

aminonaphtholl-sulfoacid, which dyestufl Signed by us at Dusseldorf this6th day of forniis aldgfk powder Wlfih hmeilsallic, luster,December'1907. easi y so u e in Water, W ic so ution is not changed byaddition of some caustic soda lye, 5 soluble in concentratedsulfuric-acid with greenish-blue color; and dyeing cotton andW'itnesses: wool bright blue shades, substantially as WILHE M FLAsoHE,hereinbefore described. CLEMENS HECKMANN.

